Some rocky exoplanets could have huge amounts of water in their molten cores

Illustration of a molten exoplanet, with its fiery yellow-orange star in the near background.

As much as 95% of an exoplanet's water could be trapped forever deep inside its iron core, transforming what we thought we knew about water worlds and potentially rendering them even more habitable than we realized.

"Planets are much more water-abundant than previously assumed," said Caroline Dorn, who is professor of exoplanets at ETH Zurich in Switzerland, in a statement.